Related Field
One or more embodiments relate to a touch driving signal generating device, a touch driving device including the same, and a display device and a driving method thereof, for reducing power consumption.
Discussion of the Related Art
Touch panel is a type of input device, which may be included in an image display device such as a liquid crystal display (LCD) device, field emission display (FED), plasma display panel (PDP), electroluminescent display (ELD), electrophoretic display (EPD), organic light emitting display device, etc., and enables a user to input information by directly touching a screen with a finger, a pen, or the like while looking at the screen of a display device. Touch panels are used as input devices of various products such as televisions (TVs), notebook computers, monitors, etc., in addition to portable electronic devices such as electronic notebooks, e-books, portable multimedia players (PMPs), navigation devices, ultra-mobile personal computers (UMPCs), mobile phones, smartphones, tablet personal computers (PCs), watch phones, mobile communication terminals, etc.
Recently, the demand for in-cell touch type display devices has increased. In-cell touch type display device includes a plurality of elements that configure a touch panel and are built into a display panel.
FIG. 1 is a waveform diagram showing signals applied to a related art in-cell touch type display device.
Referring to FIG. 1, the related art in-cell touch type display device temporally divides one frame into an image display period DP and a touch sensing period TP according to a touch synchronization signal TSS.
The related art in-cell touch type display device sequentially supplies a gate signal GS to a plurality of gate lines GL1 to GLm during the image display period DP, respectively supplies data voltages synchronized with the gate signal GS to a plurality of data lines DL1 to DLn, and supplies a common voltage Vcom to a plurality of touch electrodes TE used as common electrodes, thereby displaying an image.
Moreover, during the touch sensing period TP, the related art in-cell touch type display device supplies a touch driving signal TDS to the touch electrodes TE to sense a user touch. At this time, the touch driving signal is also supplied to the gate lines GL1 to GLm and the data lines DL1 to DLn.
The related art in-cell touch type display device supplies the touch driving signal TDS to the gate lines GL1 to GLm and the data lines DL1 to DLn during the touch sensing period TP to decrease a load of each of the touch electrodes TE, thereby enhancing a touch sensitivity. For example, in the touch sensing period TP, since the touch driving signal TDS is supplied to the touch electrodes TE, the gate lines GL1 to GLm, and the data lines DL1 to DLn, a parasitic capacitance does not occur among the touch electrodes TE, the gate lines GL1 to GLm, and the data lines DL1 to DLn. Accordingly, a touch sensitivity is enhanced.
However, even when a touch does not occur during the touch sensing period TP in one frame, the touch driving signal TDS is output to the gate lines GL1 to GLm and the data lines DL1 to DLn. Thus, the related art in-cell touch type display device has the same power consumption irrespective of whether there is a touch.
For this reason, in the related art in-cell touch type display device, power is consumed, even when the in-cell touch type display device is not touched.